Technical Field
The present invention relates to a surveying technique.
Background Art
For example, a technique for obtaining a three-dimensional model of the topography of an object based on image data (three-dimensional topographic data in which the topography of the object is modeled as electronic data) is publicly known (for example, refer to Japanese Unexamined Patent Application Laid-Open No. 2013-96745). The image data may be obtained by photographing a civil engineering worksite or the like from the air. In such a technique, information of photographing locations must be linked with the photographing data.
In the above technique, a method of using an autonomously flying unmanned air vehicle (UAV) equipped with a camera may be used. In this case, the clock included in the camera is synchronized with a GNSS unit (location identifying unit using a navigation satellite) and an IMU (inertial navigation unit), which are mounted on the UAV. Then, a relationship between an obtained still image (frame image in the case of using a moving image) and a location and an attitude of the camera (UAV) is obtained.